"Just arm the teachers. I'm sure it's in the school budget," he joked. "Sorry your school cant afford enough copies of 'To Kill a Mockingbird,' but good news, here's something that can kill any bird. Now."

Colbert also criticized POTUS for holding a "cheat sheet" during his listening session with survivors and family members of those killed with a reminder to tell them, "I hear you."

"People have cheat sheets, but it is a little unsettling the president needs a cheat sheet for other people's emotions," he said. "I can imagine the cheat sheets he used for his ex-wives!"

The host then turned his attention towards Rubio and his performance during CNN's Town Hall on gun reform.

Calling Rubio a "Florida senator and man who just received his cash from the NRA," Colbert pointed out that the crowd "wasn’t exactly with" him during the event. "And you know what they say: If they're not with you, you're Marco Rubio," he joked.

During the panel, Rubio received unwelcome applause for saying that in order to ban some semi--automatic weapons, "you would literally have to ban every semi-automatic rifle that's sold in America."

"That is a guy who cannot read the room," said Colbert. "Look, we'd have to get rid of guns and that's a slippery slope to fewer dead people. Oh, you'd like that? Fair enough. I guess it takes all kinds."

Colbert also called out some of the reporters calling the senator "brave" and commending him for showing up in the first place.

"OK, here’s the thing, just showing up isn't that impressive," he said. "He works for those people. If your boss calls you into their office, you can't say, 'Yes, I hit a customer, yes, I turned turned the break room into a sex dungeon and yes I'm currently very high. But I showed up even though I knew you'd be mad. I should get some credit for that. Do you wanna get high?'"